Double Diaphragm Air Pump
Double diaphragm air pumps, which can be used to transfer all kinds of products including high-viscosity, corrosive or aggressive fluids, are one of the preferred pumps in many fields of industry such as pharmaceuticals, cosmetics, ceramics, food, treatment plants, cutting facilities, shipyards, chemical products, paint shops and mining sector. Thanks to its simple working principle and suction capability, diaphragm pumps can easily meet the demands of heavy-industry applications.
According to the chemical properties of the fluid to be pumped, Polypropylene, Aluminum, 316 Stainless Steel and PVDF body options are available. They are self-priming and dry-running pumps.
- Easy to install
- Easily portable
- Can operate underwater
- Can operate dry
- Solid particle permeability of max. 0.50” (12.7 mm) for aluminum and 316SS, max. 0.35” (8.9 mm) for Polypropylene and PVDF
- Suitable for aggressive chemicals
- Max. 908 Liter/minute flow rate for Aluminum and 316SS, max. 583 Liter/minute flow option for Polypropylene and PVDF
- Suitable for high-viscosity products
- ½”, 1”, 1 ½”, 2” and 3” size options
- A more economical solution than other positive displacement pumps
After the Magnetic Driven (Glandless) Centrifugal Pumps and Barrel Pumps, FINISH THOMPSON also started the production of Double Diaphragm Air Pumps.
Unlike other positive displacement pumps, this does not damage the pump as the pump stops when the pump’s discharge line is closed for any reason. Depending on the size of the pump, solid particles can also pass through it.
Diaphragm pumps can be widely used in many different industries and can transfer an extremely wide range of fluids. These pumps are considered as positive displacement pumps because they create a constant flow without changing the flow rates too much. These types of pumps are used to transfer low, medium or high viscosity liquids and liquids with solid particle content. Besides diaphragms, diaphragm pumps can be designed with a wide variety of casing materials, so they can transfer a wide range of aggressive and hazardous chemicals such as acids.
What is a Diaphragm Pump?
A diaphragm pump is a hydraulically or mechanically actuated positive displacement pump that uses a combination of reciprocating motion in a linear plane and a vane valve or a ball valve to transfer fluids. Diaphragm pumps are self-priming and ideal for viscous liquids. Diaphragm pumps are used by almost all industries. They are often used to transport corrosive liquids including chemical sludge, acids and chemicals. They are also common on ships and in the ceramics industries.
Diaphragm pumps are essentially sealed. There is no gasket between the wetted parts and the outside environment. Therefore, leakage can only occur when a diaphragm fails. Without internal seals or moving components that require lubrication and cooling, a diaphragm pump can be run dry for extended periods of time without damage. They are also self-priming. Diaphragm pumps consist of one or more pump chambers that are alternately filled and emptied by the action of flexible diaphragms and check valves at the inlet and outlet. The pumping action has two phases: suction and compression/discharge phase, which causes impacts on the fluid as the product is compressed in the compression/discharge phase. This effect can be reduced by using two or more diaphragms in sequence. The air-operated double diaphragm pump is the most common of this type, but its operation is limited by the pressure of the air source.
What Does a Diaphragm Pump Do?
Diaphragm pumps use the up and down movement of a hollow, elastic surface to create fluid flow. The surface inside this pump is typically made of Polytetrafluoroethylene (PTFE or Teflon), synthetic rubber, or a similar material. When the surface is pushed into the liquid, the pressure exerts pressure on the liquid and is replaced by diaphragms, allowing a certain amount of liquid to exit. When it is withdrawn from the liquid, it absorbs the liquid at the same rate thanks to the pressure difference it creates. Diaphragm pumps use check valves to prevent backflow of liquid through the inlet valve. In air diaphragm pumps, this process is provided by balls and ball seats, it acts as a kind of check valve.
Diaphragm pumps can be used to measure, dose and transfer liquids, depending on their type. They are suitable for corrosive or non-corrosive liquids. Diaphragm design, wear that may occur due to wear or corrosion, etc. should be chosen for specific situations.
Diaphragm pumps contain either hydraulic fluid or pistons to control the movement of the diaphragm. Low lift, low pressure pumps are designed to transfer thick, viscous liquids such as slurries or heavy oils, while others are designed for high flow applications and high pressures. For example, Teflon (PTFE) diaphragm pumps are used for high precision, high pressure or high augmentation industrial applications.
What are the Diaphragm Pump Types?
Alternatively, in double-acting (double diaphragm) pumps that use compressed air to drive two separate diaphragms, the air flow is switched between the diaphragms via a shuttle valve. The flow amount can be changed by adjusting the air pressure supplied to the pump.
Double acting, in other words, double diaphragm pumps have two diaphragms and two sets of valves. Air-operated diaphragm pumps can be characteristically described as double-acting.
Where is the Air Diaphragm Pump Used?
Diaphragm pumps are used for cleaning oil and sludge in petroleum products tanks; It is widely used in the transfer and circulation of all kinds of chemicals, solvents, adhesives, paints and inks. Since air pumps work without electricity, they have ex-proof features that are safe against situations such as combustion and explosion. They are preferred to be used in the transfer and storage of paint and glue raw materials. The use of air pumps in the food industry is very common. It is used for transferring sensitive liquids such as milk, cream, mayonnaise, buttermilk, mustard and ketchup, as it does not spoil or thin the chemical properties of the liquids it transfers.
At the same time, it is possible to use air pumps in the ceramic industry, for mud transfer, for filling into molds, and for spraying and circulation in the glaze coating process. The air diaphragm pump transfers virtually any slurry, debris laden waste, food processing waste, liquid, stones, sticks, sugar, oil sludge, refinery waste, sludge, clay pharmaceutical, industrial liquids and much more.
It is also common for diaphragm pumps to be used in shipbuilding and repair. The usage areas include the discharge of bilge waters, scraping and sandblasting wastes, and rusty wastes. It is preferred to use air pumps for the transfer of many chemical substances in dyehouses in the textile sector or for the circulation of dye in printing machines.
They can be used in machining, painting booths, auto service stations, transferring boron oils, removing spray waste residues and paints, collecting sump residues and burnt oil, pumping industrial wastes and sewage to treatment plants. It is also possible to use air pumps in the dewatering of sedimentation sludges of sedimentation ponds by pressing filter presses by transferring sludge containing various acid and chemical wastes that occur in treatment plants.